The Hot Rods 4034 Stroker Crankshaft is a high-quality replacement crankshaft designed for 2002–2011 Yamaha YZ85 motorcycles. It provides an effective alternative to a costly OEM crankshaft while delivering dependable performance, durability, and improved displacement potential. This complete assembly is supplied ready for installation with proven Hot Rods connecting rods, top-end bearings, and crankshaft webs.
Factory assembled and trued to OEM specifications, the Hot Rods 4034 crankshaft is engineered to meet or exceed original-equipment standards. Its increased stroke can help produce greater displacement and horsepower, while the drop-in design requires no modification in most applications. The assembly is CNC machined and dynamically balanced to accommodate the additional stroke and uses the stock piston in most applications. For further performance gains, it can be paired with a Cylinder Works Big Bore cylinder.
Built for long-term service, this crankshaft features gears manufactured to DIN Class 9 or higher quality standards and is fully rebuildable with genuine Hot Rods connecting rods and bearings. The Hot Rods brand and manufacturer part number 4034 identify this assembly for proper replacement and service reference. Vendor part number 421-4034. Fitment includes 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, and 2011 Yamaha YZ85 models.
Features:
- Complete Hot Rods 4034 stroker crankshaft assembly ready for installation
- Fits 2002–2011 Yamaha YZ85 models
- Increased stroke supports greater displacement and horsepower
- Drop-in replacement requiring no modification in most applications
- Includes Hot Rods connecting rods, top-end bearings, and crankshaft webs
- Factory assembled and trued to OEM specifications
- CNC machined and dynamically balanced for the increased stroke
- Uses the stock piston in most applications
- Compatible with Cylinder Works Big Bore cylinders for additional performance gains
- Fully rebuildable with genuine Hot Rods connecting rods and bearings
- Gears manufactured to DIN Class 9 or higher quality standards
- Manufacturer part number: 4034
- Vendor part number: 421-4034
Fitment:
2002 Yamaha YZ85
2003 Yamaha YZ85
2004 Yamaha YZ85
2005 Yamaha YZ85
2006 Yamaha YZ85
2007 Yamaha YZ85
2008 Yamaha YZ85
2009 Yamaha YZ85
2010 Yamaha YZ85
2011 Yamaha YZ85
2012 Yamaha YZ85
2013 Yamaha YZ85
2014 Yamaha YZ85
2015 Yamaha YZ85
2016 Yamaha YZ85
2017 Yamaha YZ85
2018 Yamaha YZ85